What are the components of a reflex arc?
- Receptor - sense organ in skin, muscle, or other organ.
- Sensory neuron - carries impulse towards CNS.
- Interneuron - carries impulse within CNS.
- Motor neuron - carries impulse away from CNS.
- Effector - structure by which animal responds (muscle, gland, etc).
A reflex is a rapid, involuntary response to a stimulus. A reflex arc is the pathway traveled by the nerve impulses during a reflex. Most reflexes are spinal reflexes with pathways that traverse only the spinal cord.
- The central nervous system is made up of the brain and spinal cord. The peripheral nervous system is made up of the nerve fibers that branch off from the spinal cord and extend to all parts of the body, including the neck and arms, torso, legs, skeletal muscles and internal organs.
- A motor neuron carries the message from the central nervous system to the effector. In a knee-jerk reflex arc the sensory neuron directly connects to the motor neuron in the spinal cord. This is called a simple reflex arc. from the spindle (receptor) to where it connects with the motor neuron in the spinal cord.
- …functional group known as the reflex arc. Sensory cells carry afferent impulses to a central interneuron, which makes contact with a motor neuron. The motor neuron carries efferent impulses to the effector, which produces the response.
A reflex arc is a neural pathway that controls a reflex. In vertebrates, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord.
- Autonomic reflexes are unconscious motor reflexes relayed from the organs and glands to the CNS through visceral afferent signaling.
- The central nervous system (CNS) controls most functions of the body and mind. It consists of two parts: the brain and the spinal cord.
- When a loud sound enters a normal ear, the stapedius muscle will contract on both sides regardless of which ear is stimulated. Therefore, the ART is a bilateral ("two side") reflex. Third, the word ipsilateral (ipsi) means "same side" and contralateral (contra) means "opposite side".
Updated: 2nd October 2019